Thanks for all the comments, everyone. I really appreciate the interest Kindelabra has had here on MobileRead. Please realize that I have a life and that this is a hobby project for me, which I really wanted to share with the community. I'll prioritize major bugfixes to the program, but will continue working on new features to make my program even better/complete. Here are some features I'd like to include in the next few versions:
- confirmation for delete collection (DONE)
- support for DRM-d books
- icons showing which books are already in a collection

possible future features:
- undo
- calibre plugin
- windows installer

@ElizabethN: it doesn't matter where you keep the program, as long as you have kindle.py in the same folder.